To investigate whether the higher or lower expressions of differentially expressed genes lead to more survival risks for patients, expression levels of genes can be dichotomized based on certain cutoff values by maximizing certain test statistics.
An optimal cutoff value can be determined by applying the following steps:
Optimal Cutoff from Analysis tab.Select marker(s) boxSurvival time and Status variableRun button to run the analysis.An optimal cutoff value can be obtained as well as hazard ratio (HR) with confidence interval, mean survival time for low and high gene expression levels, and p value for selected significance test.
#####b) Optimal cutoff value(s) A Kaplan-Meier plot can be created after dichotomize the gene expression level as high and low.